Unusual lapse in Tory character (11)
I believe the answer is:
personality
'character' is the definition.
(thesaurus)
'unusual lapse in tory' is the wordplay.
'unusual' indicates an anagram.
'lapse'+'in'+'tory'='lapseintory'
'lapseintory' anagrammed gives 'PERSONALITY'.
(Other definitions for personality that I've seen before include "Distinctive character" , "Celebrity" , "Charisma" , "Individual character" , "Individual disposition" .)